The unexpectedly high revascularization rate among patients treated with medical therapy also may help explain the similar results between the medical and endovascular groups. Nevertheless, “beyond 4.5 hours, the MR RESCUE trial does not provide data supporting the use of endovascular treatment in patients with an ischemic penumbra of any size,” said Dr. Chimowitz.
To date, MR RESCUE is the only randomized, controlled trial to test the ischemic-penumbra hypothesis for endovascular therapies, but the trial was limited by its small sample size and reliance on less effective thrombectomy devices. “Larger randomized trials will be needed to retest this hypothesis with the use of newer devices once the accuracy of perfusion imaging for identifying viable brain tissue has been more clearly established,” said Dr. Chimowitz.
—Erik Greb